They are manipulating the public through fear. Just listen to the things that the administration and its officials say, it's blatantly obvious that they are trying to keep us in a box of fear.
Plus, check this out.
http://www.cnn.com/2004/TECH/science...eut/index.html
They may not be fabricating terrorist threats in order to perpetuate the climate of fear, but they sure as hell take advantage of them.